Puffinus mauretanicus 

Scope: Global

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Procellariidae

Scientific Name: Puffinus mauretanicus
Species Authority: Lowe, 1921
Regional Assessments:
Common Name(s):
English Balearic Shearwater
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.
Taxonomic Notes: Puffinus yelkouan (Sibley and Monroe 1990, 1993) has been split into P. yelkouan and P. mauretanicus following Brooke (2004).

Identification information: 33 cm. Medium-sized, rather dark shearwater. Upperparts dark brown contrasting slightly with the dirty, variably marked brown-whitish underparts. Most individuals show dusky undertail coverts and armpits. Similar spp. Easily told from Manx Shearwater P. puffinus by lack of strong contrast between upperparts and underparts. Dark individuals could be mistaken for Sooty Shearwater P. griseus but always show a white belly patch and lack the scythe-like wings and heavier flight of that species.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A4bcde ver 3.1
Year Published: 2015
Date Assessed: 2015-10-01
Assessor(s): BirdLife International
Reviewer(s): Symes, A.
Contributor(s): Andrews, D., Arcos, J., Blasco, J., McMinn, M., Oro, D., Porter, R. & Tanner, K.
Facilitator/Compiler(s): Benstead, P., Bird, J., Calvert, R., Derhé, M., Harding, M., Lascelles, B., O'Brien, A., Peet, N., Symes, A., Martin, R & Ashpole, J
This species has a tiny breeding range and a small population which is undergoing an extremely rapid population decline owing to a number of threats, in particular predation at breeding colonies by introduced mammals and at-sea mortality as a result of fisheries by-catch. Population models predict an extremely rapid decline over three generations (54 years), qualifying the species as Critically Endangered. However, this assumption was based on the existence of a population of c. 2,000 breeding pairs, which could have been underestimated according to recent population estimates and records at sea, plus a recent re-evaluation of some colonies (i.e. increased accuracy in the estimates). Updated population viability analysis to re-evaluate the species's status is planned, incorporating recent population estimates and improved demographic data. Should this analysis reveal that the species is declining at a more moderate rate, this species will warrant downlisting.

Previously published Red List assessments:

Geographic Range [top]

Range Description:The species breeds in the Balearic Islands, Spain. The breeding population was most recently estimated at 3,200 pairs which equates to 6,400 mature individuals (BirdLife International 2015). This figure is significantly larger than previous estimates of 2,000-2,400 pairs recorded in 2005 (Jones et al. 2008) but this is primarily due to increased survey effort (better prospecting of known breeding sites plus discovery of new sites) and does not reflect a genuine increase of the population. The islands of Mallorca have 900 pairs; Cabrera 449 pairs; Menorca 405 pairs; Ibiza 747 pairs and Formentera 692 pairs (Arcos 2011a). The world population was until recently believed to number 8,000-10,000 individuals (Louzao 2006a, Wynn and Yésou 2007), however recent winter at-sea surveys and counts from Gibraltar of post-breeding birds leaving the Mediterranean suggest the total population may in fact lie within in the range 20,000-30,000 individuals (Arcos 2011b, Arroyo et al. 2015). This is supported by a count of at least 16,400 individuals off Valencia in December 2009 (Aleixos 2012). Reasons for the discrepancy between breeding and non-breeding population estimates are unclear, but it is most likely that this species has a particularly large floating population of immatures and non-breeders.

On Cabrera Island, 60% of the colonies have disappeared in the last few decades, while colonies on Formentera have experienced a strong decline in recent years, from more than 1,500 breeding pairs in the early 1990s to less than 1000 pairs in 2001 (Ruiz and Martí 2004) and 692 pairs in 2003-2006 (Arcos 2011a). Population viability analysis has shown that in the presence of environmental and demographic stochasticities, mean extinction time for the world population was estimated at 40.4 years, and mean growth rate showed a 7.4% decrease each year (Oro et al. 2004). However, this model was run using the earlier population estimate of c. 2,000 breeding pairs and so new analysis of extinction risk using the updated population estimate and improved demographic data is required. At the end of the breeding season, birds may forage in areas off the coast of north-west Africa (Louzao et al. 2012). In winter, it occurs in the Balearic Sea and off the north-east Spanish coast with most of the population traditionally concentrated between Valencia and Catalonia from November to February, although recent data suggest that some birds remain in the Atlantic. For instance, in winter 2007/2008 significant numbers (with a peak count of 710 birds) remained off the coast of Brittany (France), perhaps in response to unusual sea surface temperatures (Plestan et al. 2009). Some birds migrate north in summer to seas off the British Isles and the south of the Scandinavian Peninsula (Wynn et al. 2007). Numbers recorded in the traditional post-breeding quarters have declined since the mid-1990s, with a corresponding increase in numbers along the coasts of northern France and south-west U.K. (Wynn and Yésou 2007, Wynn et al. 2007) (including an exceptional gathering of 4,600 in the Baie de Lannion, Brittany in August 2010) (D. Andrews in litt. 2010).

Countries occurrence:
Algeria; France; Gibraltar; Ireland; Morocco; Portugal; Spain; United Kingdom
Belgium; Cape Verde; Denmark; Germany; Israel; Italy; Netherlands; Norway; Poland; Sweden; Tunisia
Present - origin uncertain:
Albania; Bosnia and Herzegovina; Croatia; Egypt; Faroe Islands; Greece; Libya; Malta; Monaco; Montenegro; Slovenia
Additional data:
Estimated area of occupancy (AOO) - km2:9Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:4830000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:11-100Continuing decline in number of locations:Yes
Extreme fluctuations in the number of locations:No
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The breeding population was most recently estimated at 3,200 pairs which equates to 6,400 mature individuals (BirdLife International 2015). However, winter at-sea surveys along the Iberian Shelf as part of the LIFE project to identify marine Important Bird Areas produced an estimate of 25,000-30,000 individuals (Arcos 2011b), counts of >18,000 birds past Gibraltar in May-July 2008 were extrapolated to a total of 20,000-25,000 individuals (Arroyo et al. 2011) and surveys in the Strait of Gibraltar in May-July 2007-2010 produced an estimate of a minimum of 24,000-26,500 individuals (Arroyo et al. 2015). These data are difficult to reconcile, but a precautionary estimate of 9,000-13,000 mature individuals is considered appropriate (Arcos 2011b, Arcos et al. 2011).

Trend Justification:  Using the previous population estimate of 2,000-2,400 breeding pairs, Oro et al. (2004) estimate a mean decline of 7.4% per year and a mean extinction time, as estimated by population viability analysis, of just over 40 years. This equates to an ongoing population decline of more than 80% in three generations (54 years). However, an updated population viability analysis is necessary to re-evaluate the population trend, taking into account the new population estimate and improved demographic data (particularly adult survivability estimates). While the new information on population size could smooth the decreasing trend, adult survival could be even lower than assumed by Oro et al. (2004), given that their analysis did not take into account colonies subject to predation (Arcos 2011a).

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:9000-13000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:1Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:Yes
No. of individuals in largest subpopulation:100

Habitat and Ecology [top]

Habitat and Ecology:It breeds on cliffs and small islets, is very philopatric, and lays only one egg. Adult birds do not commence breeding until their third year (Oro et al. 2004). Breeding takes place between February and June (Ruiz and Martí 2004). When raising young, adult birds form concentrations on the east coast of Spain (Arcos and Oro 2002), where they mostly inhabit the productive continental shelf and associated fronts where high prey concentrations occur around the Ebro Delta (Louzao et al. 2006b). Most birds leave the Mediterranean for a post-breeding moult in the Atlantic coast of south-west Europe, mainly Portugal, north-west Spain and the Bay of Biscay (Ruiz and Martí 2004, Ramírez et al. 2008, Arcos et al. 2009). Feeds mainly on small shoaling fish, squid and crustaceans (del Hoyo et al. 1992).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):18
Movement patterns:Full Migrant
Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): This is a long-lived species and therefore immediate threats affect adult mortality rates. Adult survival is the main conservation concern, as this is unusually low for a Procellariiform (Oro et al. 2004). In accordance, the main threats identified are predation by introduced carnivores such as cats, martens and genets in the breeding colonies (Arcos and Oro 2004, Ruiz and Martí 2004, Jones et al. 2008, Arcos 2011a), and fisheries by-catch at sea (Arcos 2011a). The species's gregarious behaviour and its close association with fishing boats means that occasional "mass mortality" is likely to occur when long-line boats fish close to flocks (Arcos et al. 2008), and it appears that bycatch is fairly common but often occurs on an irregular basis, suggesting that estimates derived from observations on a limited number of trips onboard fishing vessels could be largely underestimated (Boue et al. 2013). Increasing evidence on this has been compiled in the last few years, with events of up to a hundred or more birds caught in a single event, in occasions involving other fishing gear such as purse-seiners (ICES 2008, Louzao et al. 2011) and trawlers (Abelló and Esteban 2012).

Also due to the congregatory behaviour of the species, acute pollution events, such as oil spills, pose a very serious threat, as a large number of casualties could result from a spill occurring in a congregation area (Ruiz and Martí 2004, Gutiérrez 2011). Other threats include: the reduction of prey due to fishing overexploitation; a potential reduction in fishing discards (an alternative to the overexploited natural prey) and/or anthropogenic environmental change (Arcos 2011a); habitat degradation and disturbance in the breeding grounds; background pollution (Oro et al. 2008); the development of marine windfarms (Arcos 2011a); human harvesting (nowadays a relict activity); and light pollution which disorientates fledglings (Rodríguez et al. 2015). Predation by Peregrine Falcons Falco peregrinus in the breeding colonies has also been recently reported (García 2009, Wynn et al. 2010), though this should be considered as a factor of natural mortality that likely has little influence on the decline of the species. The gradual northward movement of the non-breeding population may be affecting adult survival, and this shift may be due to climate change or alterations in fish distributions as a result of fisheries' activities (Yésou 2003, Wynn and Yésou 2007). The recent demographic decline has not yet decreased the species's genetic variability, and connectivity found among colonies at least does not exacerbate the species's extinction risk (Genovart et al. 2007).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
All breeding sites are currently protected as Special Protection Areas (SPAs) under the Natura 2000 network, with the unique exception of the colony of Punta Prima in Formentera, where new information has revealed that the prevailing colony (50 pp.) lays right outside the SPA (and the overlapping Important Bird Area, IBA) designated for this species. The management plans for the Balearic SPAs have not been implemented yet. Management plans are therefore limited to colonies covered by other designations, such as the National Park of Cabrera and the Natural Park of Sa Dragonera. Rat eradication campaigns have been conducted at several colonies, including Cabrera archipelago and Dragonera Island, where 15 months after a programme of aerial bait drops in 2011 no rats or mice had been detected (Mayol et al. 2012). Less effort has been directed at the most concerning colonies where carnivores are present (e.g. Formentera and Menorca). 

At sea, the Spanish Government has started the process of SPA designation based on the inventory of marine IBAs conducted by SEO/BirdLife, which, once concluded, will provide protection to the main hotspots for the species in Spanish waters. So far, only a few small coastal sites have been designated as SPAs by the regional governments in Spain. Portugal already has an inventory of marine IBAs, but their designation as SPAs is still pending. Finally, France has also proposed a network of SPAs that include hotspots for the species. Management plans for all the marine SPAs are still pending.

Action Plans for the species have been published at local, national or international level in 1991, 1999, 2004, and 2005 (Jones et al. 2008). A LIFE project for the species ran from 1991-2001 (Ruiz and Martí 2004), and Spain and Portugal had a joint LIFE project running from 2004-2008 aimed at identifying marine IBAs, including for this species (Ramírez et al. 2008, Arcos et al. 2009). A number of actions have been implemented through Species Guardians SEO/BirdLife and SPEA as part of BirdLife's Preventing Extinctions programme including: coordinated coastal and boat-based counts, gathering information to assess the impact of bycatch on the species, communicating and disseminating information on the species and contributing to the updated Species Action Plan published in 2011 (SEO/Birdlife and SPEA 2013). Research on the species is being conducted by BirdLife partners in collaboration with several research centres, with funding from EC projects LIFE+ INDEMARES (Spain) and Interreg FAME (Portugal, Spain, France, UK and Ireland). The main initiatives include the assessment of bycatch through questionnaires to fishermen, observers on board fishing vessels and conducting of beached bird surveys; and the identification of hotspots at sea through boat surveys, coastal counts and tracking studies (breeding and non-breeding grounds).

Conservation Actions Proposed

Control and eradicate introduced predators (with particular emphasis on carnivores) in breeding colonies identified to be at risk. Implement biosecurity measures to prevent introduced predators from re-establishing. Thoroughly study the problem of bycatch by long-line fishing and develop awareness campaigns directed at the fishing sector, in order to mitigate this threat, plus assess and implement the appropriate mitigation measures. Ensure effective protection for nesting sites and marine hotspots, and the implementation of monitoring schemes and management plans. Develop a rapid response plan for a potential oil spill close to main feeding and breeding areas. Raise awareness and stop human exploitation. Study small pelagic fish populations in the western Mediterranean and in the Bay of Biscay to assess extent of over-exploitation and how this affects the species. Assess the impact of pollutants and heavy metals on this species. Increase awareness of the negative impacts of light pollution near breeding colonies. Improve understanding of at-sea distribution, including during the non-breeding season. Conduct research to better understand the reasons for the discrepancies between breeding and non-breeding population estimates (Arroyo et al. 2015).

Citation: BirdLife International. 2015. Puffinus mauretanicus. The IUCN Red List of Threatened Species 2015: e.T22728432A82342251. . Downloaded on 04 December 2016.
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